Sodium Bicarbonate → 4-{[2-(4-Chloro-2,6-dimethyl-phenyl)-acetyl]-hydroxy-amino}-1-methoxy-piperidine-4-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (4-chloro-2,6-dimethyl-phenyl)-acetyl chloride (2.90 g, 13.4 mmol) in THF (25 ml) was added sodium hydrogen carbonate (1.90 g, 22.7 mmol) at 0° C., followed by 4-hydroxyamino-1-methoxy-piperidine-4-carboxylic acid methyl ester (preparation example 11, step 3; compound P4ii.2) (2.73 g, 13.4 mmol) dissolved in THF (25 ml) dropwise. The reaction mixture was stirred at 0° C. for 30 minutes, then further 30 minutes at room temperature. After completion of the reaction indicated by TLC and LC/MS, the reaction mixture was filtered and the residue (NaCl) washed with THF. The filtrate was concentrated to dryness and stirred several times with little amounts of an ether/hexane mixture (1:1) to remove side products. Finally, the compound was washed with ether to yield pure 4-{[2-(4-chloro-2,6-dimethyl-phenyl)-acetyl]-hydroxy-amino}-1-methoxy-piperidine-4-carboxylic acid methyl ester (compound P3ii.34) as white solid. Yield: 3.7 g, mp 228-231° C.

Provenance & Evidence